The transportation industry continues to require methods of baffling, reinforcement and sealing that provide improved functionality while simultaneously providing reduced weight and cost. Often, when attempting to reduce the weight of a part, the use of dissimilar materials in combination provides the requisite baffling, reinforcement, and/or sealing, while achieving an overall reduction in weight. As a result, numerous challenges arise from attempts to combine and attach dissimilar materials. In the event that such combinations of dissimilar materials are not properly secured to one another, the part may fail to fill a cavity as intended.
Existing methods for securing dissimilar materials to one another are taught in U.S. Pat. No. 6,131,897. The '897 patent teaches insertion of a strip of uncured thermally expandable material into a channel formed within a carrier. Additional methods are disclosed in U.S. Pat. No. 8,413,611 which teaches well-known post and tab structures extending from a support flange surrounding a marginal rim of a baffle structure. That patent also teaches the importance of avoiding any expandable material over an inner portion of its synthetic resin carrier. In this regard, the patent appears to deem it critical that the expandable band be continuously circumscribing. Many designs and structures for improving attachment between a carrier and second dissimilar material require complex tooling and geometries and further fail to effectively achieve the desired sound deadening, vibration damping or reinforcement. There is thus a need for improved means of securing dissimilar materials to one another, while utilizing simplified tooling and manufacturing processes. Further, according to the latter patent, the requirement of a continuous peripheral band and the avoidance of expandable material over the interior area forecloses any attachment techniques by which either coverage over an interior portion, an attachment of material to the carrier in the interior area, or both, is possible. This accordingly limits the utility of resulting parts. For example, a part having expandable material over an interior portion appears to be prevented by the teachings of U.S. Pat. No. 6,413,611. It is therefore desirable to make a part that allows at least partial coverage of an interior portion with an expandable material while also providing secure attachment of expandable material to the carrier.